Overwintering guide
How to overwinter dahlia 'penhill watermelon'
Winter watering
Water rarely, and only in dry spells — winter wet is a bigger risk than winter cold. Make sure containers drain freely.
The mistake that kills dahlia 'penhill watermelon' in winter
Leaving dahlia 'penhill watermelon' in a pot standing in a saucer of water. Waterlogged compost freezes solid around the roots and kills plants that would have survived the cold perfectly well.
More dahlia 'penhill watermelon' care
Overwintering dahlia 'penhill watermelon' — FAQ
Does dahlia 'penhill watermelon' need to come indoors for winter?
Dahlia 'Penhill Watermelon' is hardy to roughly USDA zone 8 — winter lows around -12°C. That means it survives outside in mild areas, but wants shelter in a hard winter. Dahlia 'Penhill Watermelon' can stay outside over winter in most areas, but appreciates some protection in a cold snap. Mulch generously over the root zone, move containers against a sheltered wall (pots freeze far harder than open ground), and have horticultural fleece ready for the worst nights. The roots are what you are protecting — top growth can be sacrificed and regrown.
When should I move dahlia 'penhill watermelon' for winter?
Mulch and move pots into shelter in late autumn, before the first hard frosts.
How often should I water dahlia 'penhill watermelon' in winter?
Water rarely, and only in dry spells — winter wet is a bigger risk than winter cold. Make sure containers drain freely.
What kills dahlia 'penhill watermelon' over winter?
Leaving dahlia 'penhill watermelon' in a pot standing in a saucer of water. Waterlogged compost freezes solid around the roots and kills plants that would have survived the cold perfectly well.